Country Presentation Nepal

Transcription

1 Country Presentation Nepal TRAINING WORKSHOP ON CALIBRATION AND MAINTENANCE OF METEOROLOGICAL INSTRUMENTS IN RA II (ASIA) 2013 Chiranjibi Bhetuwal Meteorologist Department of Hydrology and Meteorology (DHM), Nepal

2 Turkmenistan Afghanistan Nepal: Location Area: 147,181 km 2 Length: 885 km EW Width: 193 km NS Altitude: m China Iran Pakistan Nepal Bhutan Oman India Bangladesh Myanmar Laos Thailand Cambodia Kilometers Kilometers Sri Lanka Malaysia

3 Physiographic Regions Physiographic Division Terai Region Siwalik Region Mahabharat Region High Mountain Region Higher Himalayas Region NEPAL PHISIOGRAPHIC DIVISION Kilometers A wide range of climatic conditions from subtropical in the southern plain area to polar and arctic in the high Himalayas are found in this country Terai hottest part, summer temp. may rise as above 40 C and winter temp is above 5 C Mountains mild summer, sub-zero to 12 C in winter Himalayas Coldest part, snow all year round Cross-section of Nepal s topography

4 Department of Hydrology and Meteorology (DHM) Mandated from Government of Nepal to monitor all the hydrological and meteorological activities in Nepal.

5 Organizational Structure of DHM Professional Staff : 60 Technicians :143 Administrative Staff :30 Total Staff :233 Instrument section S.D.M 1 Meteorologist 1 Electronic Engineer 1 Met Assistant 2

6 Existing Observational Network of DHM A. Manual Stations Precipitation stations 173 Climatic Stations 72 Agro-meteorological Stations 21 Synoptic 9 Aero-synoptic Stations 7 Hydrometric stations 154 sediment stations 20

7 Major Data gap region and the high Himalayas

8 Automatic Surface Observation systems 1. Automatic weather stations near real time data 14 stations (Air temp, R.H., Precipitation, atm. Pressure, wind speed and direction, solar radiation) 2. Automatic stations near real time data 7 stations (air temp, R.H. Rainfall) 3. Automatic rainfall stations near real time 51 stations (Data transmission is through GPRS, CDMA system in every minute depending on site) 4. Automatic weather stations offline about 7 stations 5. Automatic real time river gauge stations 31 stations 6. Few automatic weather stations with iridium satellite data transmission facility are under installations in high altitude

9 Existing Automatic meteorological stations parameters A. Automatic observing stations near real time S.N. Observed parameter No of stations 1 Rainfall 73 2 Air temperature and relative humidity 21 3 Wind speed and direction 14 4 Atmospheric pressure 12 5 Global Solar radiation 9 B. Automatic weather stations offline 7 Data from all the automatic stations quality controlled in real time

10 Quality Control of Data Web based new database system (PostgreSQL 9.0) in Linux based environment installed in 2011 with support from Finnish Meteorological Institute. Database server is installed at National Information Technology Center (NITC) Nepal. The database can handle both manual and automatic real time data from AWSs. Quality control is done in real time (every 2 minutes). Data has to pass through different quality control stages 1. QC0 done at the station (for manual and some automatic stations) 2. QC1 done as soon as observation enters database 3. QC2 done later, when all neighboring stations have observations etc (not implemented yet) 4. HQC done much later (Human Quality Control)

11 Quality Control (QC1) Steps on QC1. This is done in data base 1. Persistency check:- to check whether data is changing or not (Data values should change with time) 2. Step change:- the data value should not jump suddenly 3. Consistency test:- Relation between two or more parameters (example Visibility and Present weather should match) 4. Compare test: Compare the values between two variables (Maximum temperature>minimum temperature) 5. Limit test:- General valus limit for different parameter (temperature between - 80 to 60 degc and so on) After applying the quality control data is quality flagged with different flag no for diff quality of data

12 Instruments on Operational Use Atmospheric Pressure a. Manual a.1 Mercury Barometer Manufacturer 1: Dr. A. Muller, R. Fuess Germany Model: Kew pattern type: 11 b9 Manufacturer 2 : Lambrecht, Germany Model: Kew pattern type: 611 Manufacturer 3 : India Meteorological Department, India Model: Kew pattern type b. Automatic 1. Environdata Australia Pressure sensor ( These sensors will be replaced with new ones ) 2. Vaisala OYJ, Finland Capacitive absolute pressure sensor BAROCAP PTB 110 SENSOR Capacitive absolute pressure sensor BAROCAP PTB330 Sensor WXT 520 Compact sensor (Barocap pressure module) Mercury Barometer Pressure sensor

13 Instruments on Operational Use Air temperature and Relative Humidity Manual instruments a. Manual Liquid-in-glass thermometer Manufacturer: Thermoschneider, Germany and Lambrecht Germany Models: Maximum thermometers, 1002 DIN 58654, Scale C Minimum Thermometer, 1014 DIN 58653, Scale 0.5 o C Dry and Wet bulb Thermometer, 1033 DIN 58660, Scale 0.2 o C b. Automatic automatic 1. Environdata Australia temperature sensor TA Lambrecht Germany combined temperature and humidity sensor Model No 8091 (Capacitive Humidity and Pt100 Temperature sensor) 3. Vaisala, Oyj, Finalnd HMP155 Humidity and Temperature Probe (Humicap capacitive humidity sensor and Pt100 temperature sensor) 4. Vaisala, Oyj, Finland WXT 520 Compact sensor (capacitive and pt100) 5. Rotronic Instrument Company, Switzerland, HC2S Temperature and Relative Humidity Probe

14 Instruments on Operational Use Wind speed and Direction Manual instruments a. Manual Mechanical Cup anemometer Manufacturer: Casella Manufacturer 2. :- Lambrecht, Germany Model:- Mechanical Cup Counter 1440 b. Automatic 1. Cup Anemometer: - Environdata Australia Wind speed cup sensor and wind vane (WS 30 and WS 40 WD 30, 32, 42 etc) 2. Sonic Anemometer:- a. Vaisala OYJ Finland, Ultrasonic wind speed sensor WMT 702, WXT 520 Compact sensors Ultrasonic b. Climatronics Corporation USA Sonimometer (sonic anemometer) (P/N c. R.m. Youngs 2 axis ultra sonic anemometer Propeller anemometer R.M. Youngs Company EPS PROPELLER

15 Instruments on Operational Use Precipitation measurements Manual raingauge a. Manual US stanadard Ordinary rainague Manufacturer: Local Galvanized Iron Raingauge 8inch diameter with internal cylinder and measuring stick b. Automatic Weighing gauge Manufacturer: Ott, Germany Model: Pluvio 2 version 2 and 4 (200cm2 with 1500mm capacity and 400cm2 with 750mm capacity (load cell) Tipping bucket gauge 1. Manufacturer:- Environdata, Australia 8inch diameter 2. Manufacturer: - Casella, London 8 inch diameter 3. Manufacturer: - Texas electronics INC USA TR525S.2mm 8" dia 4. Manufacturer: - TB3 Hydrological Services, Australia 5. Manufacturer:- Lambrecht, Tipping bucket (200cm2 orifice) Float gauge Manufacturer: Lambrecht Germany Weighing Tipping bucket

16 Instruments on Operational Use Solar Radiation/ Sunshine Duration b. Automatic Global solar radiation 1. Manufacturer: Kipp and Zonnen, Netherland Model: CMP6 Thermopile 2. Manufacturer: Licor silicon sensor Model: Licor PY Environdata, Australia Model: SR10 Silicon type Net Radiometer 1. Manufacturer:- Kipp and Zonnen, Netherland Model CNR4 Thermopile sensor 4 components of radiation Sunshine Recorder Campbell-Stokes sunshine recorder 1. Casella, London HB , 02271D (Tropical 0-45 deg) Sunshine cards Pawan export India

17 National Standard /Travelling Instruments Atmospheric pressure National Standard Kew pattern type mercury barometer Lambrecht, KG Gottingen Model: 611/ last calibration with a superior standard: 1992 AD with Indian standard Interval of calibration with a superior standard: No Traveling standard Precise Aneroid Barometer Baromec, Range mb Mechanis ltd, CroyCon England Type M1975 Calibration:- Intercomparision with national standard before and after field intercomparision. Wind Speed and Direction No standard Instruments Air Temperature/Relative Humidity National Standard Mercury and Alcohol thermometer Model: , Thermoschneider Germany last calibration with a superior standard: No Interval of calibration with a superior standard: No Traveling standard Vaisala Oyj, Finland, Hand-Held Humidity and Temperature Meter HM70 Model:- HMP75B G Calibrated date Jan 30/31, 2012 NIST traceable range of calibration:- -40 to 60 deg C 6 point temperature calibration and 7 point humidity calibration calibrated in measurement standard laboratory Vaisala OYJ Finland Precipitation Measuring cylinder graduated for 20cm diameter raingauge is used for field Intercomparision Global solar radiation CMP6 Pyranometer, Kipp and Zonnen, Netherland

18 Relative Humidity Hygrograph Chamber: Company: Theodor Friedrichs and company, Hamburg, Germany Parts no: , Fabr.No Calibration laboratories Air Temperature Originally Thermograph chamber(can be used for sensors as well):- Company: Theodor Friedrichs and company, Hamburg, Germany Parts no: 2391, Fabr.No Thermometer bath Intercomparision chamber: Company: Theodor Friedrichs and company, Hamburg, Germany Parts no: , Fabr.No. 8035

19 Atmospheric Pressure Barometer Intercomparision Chamber: Company: Theodor Friedrichs and company, Hamburg, Germany Parts no: 8710 Fabr.No Calibration laboratories Problems in Operation of Calibration Lab and Solutions No intercomparision of calibration instruments with international standard has been done after its establishment in 1980s. Intercomparision chambers for Barometer and thermometer bath are not in operational use these days but it can be used after comparison with international standard and necessary trainings for its operation. The calibration laboratories are not accredited, ISO and other certified. Thermograph calibration chamber is easy to operate and can be utilized for sensor calibration as it has outlet for sensor ports Modifying the design of hygrograph calibration chambers to calibrate for humidity sensors (already consulted with company and they can modify the existing design for sensor calibration) its also easy for operation. Frequent Power Outage is the main problem for operational use of Calibration Chamber in the Energy Crisis environment of Nepal Lack of Trained technical personals to do calibration

20 Immediate Plans for Calibration and Intercomparision. Purchasing high speed data logger (high speed processor (32bit or more), and 10 bit or more analog to digital converter) with enough analog (0-1v, 0- microvolt, 0-1A etc), RS232, RS485, SDI12, Frequency, Counter channels to use for calibration purpose only. Vaisala HM70 calibrater can be taken as reference for air temperature and humidity sensor calibration and the hand held calibrater will be regularly (every 2 years) calibrated in Vaisala Lab in order to ensure quality. Modifying the design of hygrograph calibration chambers to calibrate for humidity sensors (already consulted with company and they can modify the existing design for sensor calibration) Continuous Power is the main problem for now. Purchasing simple calibrator for rainfall. Purchasing hand held SOLRAD logger from Kipp and Zonnen for field intercomparision of global solar radiation sensors. Purchasing Vaisala PTB330 pressure sensor with digital display for field intercomparision back up. Purchasing recently calibrated wind speed and direction sensor (high quality sensor) for intercomparision of other sensors in head office premises.

21 Plans for Establishment of Calibration Laboratories and Problems New calibration instruments are planned to be purchased under Pilot Project for Climate Resilience (PPCR) project funded by World Bank (WMO will provide the technical support). Management of uninterrupted power supply. Lack of spare instruments, working procedure documentation (SOP and others), trained and motivated manpower. Financial constraints for regular maintenance, calibration and monitoring works.

22 Problems, Maintenance and Calibration efforts Problems in Manual Instruments 1. Leakage from Manual Raingauge. 2. Frequent Break in Alcohol column of minimum thermometers specially during winter season and break in mercury column of maximum thermometer some times. Many observers are unaware about the break in thermometer column. 3. Most of the technicians are not trained to correct the break in thermometer column. 4. Many observers always keeps the value of maximum, minimum thermometer reading after setting same as dry bulb without caring for real values of thermometers. The observers are either trained to do the same by some technical staff in order to make the data quality acceptable or some observers they try to cheat. This makes difficult to identify the real problems with thermometers. 5. Lack of training to observers and technical staffs and not taking observation on exact time. 6. Frictional effect on cup anemometer rotation and decrease in wind speed value with aging. 7. Sunshine recorder setting not done properly or changing of settings by untrained personals. 8. Regular cleaning and upkeeping of instruments and observatory not done.

23 Problems, Maintenance and Calibration efforts Efforts for maintenance in Manual Instruments 1. Thorough checking of all the instruments during visit. 2. Training to local observers and technicians for general maintenance of instruments, correcting the break in thermometer column. (particularly to minimum thermometers) 3. The efforts to provide spare thermometers, measuring cylinder and measuring stick of manual raingauge is in process as far as the budget permits. 4. Cleaning, greasing and upkeeping of instruments. 5. Proper fixing of sunshine recorder if traces on cards are not properly burning. 6. Intercomparison of instruments with travelling standards. 7. Replacing defective instruments with new one during visit. 8. Updating the Metadata.

24 Problems, Maintenance and Calibration efforts Problems in Automatic 1. The AWS is powered with solar and operated by battery back up. the failure in battery results in non-functioning of the system and hence data loss. 2. Loose connections of sensor connecters, water leaking inside cable and breakage in cable connections from sensors to data logger. 3. dust deposits, mud housings (by wasps), webs by spiders and other insects and bird nests in instruments. 4. Clogging of tipping bucket rain gauge due to bird droppings, dried leaves and twigs etc 5. Rusting in instruments. 6. The sensors are not heated type due to power problems. Very high wind speed values of more than general limit has been observed from the Ultrasonic wind sensors when the snow get deposited in between transducers. 7. Growth of trees and bushes in the observatory. 8. Block in mechanical wind sensors and difficulty in maitenance as most of the mast are not tiltable or foldable types. The breakage in wind sensor has been observed in many instances. 9. Lack of proper leveling of instruments 10. Theft of equipments like battery and solar panel in the energy crisis environment of Nepal leading to non-functional status of an AWS and hence loss of data.

25 Maintenance efforts AWS and automatic raingauge Replacing the battery with a new one, at least once in two years for uninterrupted functionality. Thorough checking of sensors, cable connections. Cleaning of sensors, rusting cleaning, greasing etc. Checking the value of solar radiation before and after cleaning. Pouring know volume of water in raingauge and checking the values. Intercomparison of values with travelling standards. Cross validation of wind speed value with beaufort scale and wind direction values with prevailing direction. Proper fixing of cables and other mechanical parts. Changing the filter of relative humidity. The problem of cable damage between tipping bucket raingauge and data logger is unknown for long time. therefore SDI interface which can do two way communication between data logger and sensor is used in tipping bucket in order to identify the cable damage (cuts due to mouse or other reasons) Carefully cross validating the sensitivity factors (for solar radiation) and tip amount in tipping bucket gauge.

26 Some Examples and Photos Cleaning temperature humidity filter Mud housing by Wasps blocking tip of raingauge Tilted wind sonic sensor Temporarily fixing the sensor during visit

27 Intercomparison Solar radiation sensor intercomparsion (Darchula 23 Nov, 2012) Vaisala HM70 in wooden stevenson screen Date 20 Nov 2012 Bajhang Chainpur AWS Lambrecht Temperature humidity sensor in radiation shield Thermometers in wooden Stevenson screen Time CMP6 Kipp and LICOR (watt/m2) Zonnen (watt/m2) Remarks:- Licor value lower than CMP6 Air Temp ( o C) Humidity(%) Temp ( o C) Humidity (%) Dry Bulb ( o C) Wet Bulb ( o C) R.H.(%) :00 AM :15PM ;48 Lambrecht temperaure higher than Vaisala